This article detected the FGL1 expression of different types of circulating tumor cells in patients with HCC, analyzed the relationship between the FGL1 expression of circulating tumor cells and the patient’s clinicopathological characteristics and prognosis, and investigates whether circulating tumor cells can be used as a substitute for tissue samples to assist in the clinical selection of patients who may benefit from immunotherapy for HCC. This evidence concerns the gene FGL1 and neoplasm.